2nd Hand Marijuana Smoke & Drug Testing

Who Uses Marijuana

These numbers are important as it is becoming increasingly likely that you may be exposed to second hand marijuana smoke with or without your knowledge. Because of this, many people are asking if 2nd hand exposure can result in a positive drug test for THC.

Testing For THC

By far the most common drug test used is urinalysis. A small sample of your urine will be tested for a number of drugs including THC. If a person has 50 ng/ml THC, or above, their test will be considered positive.

The length of time marijuana can be detected in urine varies greatly with the frequency of use. In frequent users (more than once weekly), marijuana builds up to levels above the 50 ng/ml urine detection level. It would take weeks, even months, to fall back below 50 ng/ml. Occasional users (once or less per week), will see their levels fall below 50 ng/ml within 2-3 days.

Drug Testing & 2nd Hand Smoke

Most people will not yield a positive test from 2nd hand marijuana smoke. Studies show people exposed to heavy amounts of 2nd hand marijuana smoke for up to 3 hours tested no higher than 25 ng/ml of THC. As a matter of fact, it has been shown that the only way to inhale enough second hand marijuana smoke to test positive is to remain in an enclosed area that has so much smoke that it actually irritates your eyes. You may also want to use this cool Drug Test Results Calculator from marijuanacentral.com. This calculator is very popular and known for its accuracy.